In Italian, attaching the pronoun ci to certain verbs shifts their meaning from simply doing an action to having the physical or mental capacity to do it. This little ci anchors the verb to your general ability.
Vederci
When you add ci to vedere (to see), you get vederci: to have the sense of sight, or to be able to see in a given situation (like in the penombra, dim light). You will use this verb frequently when visiting the oculista (eye doctor) or ottico (optician), or when discussing being miope (nearsighted) or cieco (blind).
| The eye doctor told me that I cannot see well. | L'oculista mi ha detto che non ci vedo bene. |
| Grandpa is more blind than nearsighted, he cannot see at all. | Il nonno è più cieco che miope, non ci vede affatto. |
| I wasn't seeing well in the dim light, so I went to the optician. | Non ci vedevo bene nella penombra, quindi sono andato dall'ottico. |
Sentirci
Similarly, sentirci (from sentire, to hear) refers to your physical ability to hear. It comes up often at the otorino (ENT doctor), when dealing with a ronzio (ringing in the ears), or when using an apparecchio (hearing aid) to catch a bisbiglio (whisper).
| The ENT doctor confirmed that now I can hear well. | L'otorino ha confermato che adesso ci sento bene. |
| With the hearing aid he can hear well, but the ringing remains. | Con l'apparecchio ci sente bene, ma il ronzio rimane. |
| I thought grandpa couldn't hear, but he heard a whisper. | Pensavo che il nonno non ci sentisse, ma ha sentito un bisbiglio. |
Capirci
Capirci takes capire (to understand) and turns it into grasping a complex situation or "making heads or tails of it." It is almost always paired with indefinite pronouns like qualcosa (something), niente, or nulla (nothing).
| Do you guys understand anything about this document? | Ci capite qualcosa di questo documento? |
| He does not want to use the hearing aid, and he doesn't understand anything. | Lui non vuole usare l'apparecchio, e non ci capisce nulla. |
| The professor explains it to himself, because we don't understand anything. | Il professore se lo spiega da solo, perché noi non ci capiamo niente. |